First download Tigase XMPP Server and extract it. You can download the official binaries, or the latest and greatest nightly builds.
$ wget http://build.tigase.org/nightlies/dists/latest/tigase-server-dist-max.tar.gz $ tar -xf tigase-server-dist-max.tar.gz $ cd tigase-server-<version>
Please do not run as root.